1. Field of Invention
The present invention relates to a method of detecting coherent noise, in particular ground roll, in acquired seismic data. Ground roll typically occurs over a particular time portion of the acquired seismic data, which portion is often referred to as the ground roll cone.
2. Description of Prior Art
An improvement of signal fidelity in seismic data acquisition requires, among other factors, an attenuation of coherent noise, in particular ground roll. A conventional method to attenuate such ground roll is the deployment of geophone arrays; the drawbacks of this conventional method are well known.
Apart from this technique of grouping geophone output signals, several other methods have been thought of to eliminate coherent noise, mainly surface waves such as ground roll, during the processing of recorded seismic data. Special, so-called adaptive, noise filter methods have been developed that yield good noise attenuation results. One of the drawbacks of such adaptive filters is that they can be applied only in that part of the data where the coherent noise dominates the desired seismic reflection energy. Outside this area, an application of adaptive filtering can deteriorate genuine reflection signals.
In order to allow the application of adaptive ground roll filtering a determination of the data area that contains dominant coherent noise is essential.